University of North Texas

About: University of North Texas is a education organization based out in Denton, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 11866 authors who have published 26984 publications receiving 705376 citations. The organization is also known as: Fight, North Texas & UNT.

Sub-wavelength interference pattern from volume plasmon polaritons in a hyperbolic medium

Abstract: Inside of a hyperbolic medium, the principal components of the permittivity tensor have opposite signs causing the medium to exhibit a ‘metallicbr’ type of response to light wave sin one direction, and a ‘dielectric’ response in the other. Our study shows that inside hyperbolic media, volume plasmon polaritons (VPPs) propagate along the characteristic planes, forming distinct, directionally dependent optical responses. This is similar to the propagation of conventional surface plasmon polaritons (SPPs) along the planar interfaces separating the isotropic dielectrics and metallic slabs. Interestingly, the plasmon polariton propagates along the resonance cone in a volume of hyperbolic metamaterial crossing the interfaces of the constitutive materials. The Young's double-slit scheme is used to study the spatially-confined diffraction in a hyperbolic slab, made of many thin planar layers of a metal and dielectric, to obtain the sub-wavelength interference pattern at the output interface. Proof-of-concept systems for producing such patterns applicable to nanolithography and subwavelength probes are demonstrated.

Subjectivity Word Sense Disambiguation

Abstract: This paper investigates a new task, subjectivity word sense disambiguation (SWSD), which is to automatically determine which word instances in a corpus are being used with subjective senses, and which are being used with objective senses. We provide empirical evidence that SWSD is more feasible than full word sense disambiguation, and that it can be exploited to improve the performance of contextual subjectivity and sentiment analysis systems.

Elevated levels and altered fatty acid composition of plasma lysophosphatidylcholine(lysoPC) in ovarian cancer patients.

Abstract: Lysophosphatidylcholine (lysoPC), a product of phosphatidylcholine (PC) hydrolysis via phospholipase A activity, has been proposed to activate cells from a number of lineages. Here, we demonstrate that lysoPC levels are significantly elevated (by 43% overall, relative to normal controls) in the plasma of ovarian cancer patients. This does not appear to be common to all cancers as 5 out of 6 leukemia patients tested had markedly lower (less than one-half of normal) plasma lysoPC. In the plasma of ovarian cancer patients, the percentages of palmitoyl- and stearoyl-lysoPC species were significantly higher, whereas oleoyl and particularly linoleoyl-lysoPC were significantly lower than in control subjects. The molar ratios of lysoPC/PC and palmitoyl-lysoPC/linoleoyl-lysoPC were also significantly elevated in the plasma of ovarian cancer patients compared with those of control subjects. Furthermore, the calculated value of plasma (lysoPC/ PC) x (palmitoyl-lysoPC/linoleoyl-lysoPC) was markedly higher in patients compared with controls.